Abstract
Previous studies show that a large part of the net energy demands of an office building is related to window heat loss and cooling demands induced by solar irradiance. Windows with improved thermal transmittance (U-value) and solar heat gain coefficient (SHGC or g-value) are important for reducing the related energy demands.
There is a scarcity of available scientific work addressing multilayer window technologies. Hence, in this study, simulations with the aim of identifying the parameters that play a key role in improving thermal performance of multilayer glazing units have been carried out. A state-of-the-art review is presented, alongside an overview of promising new products and future perspectives and improvement possibilities for multilayer glazing technologies.
It has been found that increasing the number of glass panes in the insulating glazing units (IGU) yields U-value reductions that decrease for each added glass pane. Cavity thicknesses between 8 and 16 mm were found to be optimal for IGUs with four or more panes. Reducing cavity gas thermal conductivity was found to impact IGU U-value. Improving low-emissivity surface coatings beyond the best-available technology has minor effect on U-value reductions.
In addition to the thermal performance of the glazing units, optical properties, aesthetics, ageing properties and robustness should be further studied before the use of such multilayer IGUs may be recommended. Preliminary numerical simulations have demonstrated that thermal stresses to the glazing units due to high cavity temperatures can pose a problem for the robustness and lifetime of such units.


How can researchers and planners best facilitate the transition to low-carbon societies? In particular, can they initiate better dialogue in order to foster stakeholder engagement in planning, building and living in low-carbon settlements? These challenges inform a municipal planning process for a new neighbourhood in Trondheim, Norway: Brøset, as well as for an interdisciplinary research project exploring the role of action research in supporting the transition to low-carbon societies. The processes are described for identifying the central actors and applying the dialogue strategies in the early planning project phase. Researchers and planners collaborated to contribute to new knowledge production and practice to support the transition to low-carbon societies. The utility of the co-produced results is their potential contribution to both standards of rigour as well as the timely dissemination of research and knowledge sharing within and across research communities and to different stakeholders involved in the project. This case study provides interesting lessons about why and how other projects can consider similar action research processes as a viable approach for sustaining the transition to low-carbon economies, particularly in the early planning phase.


Nå bygger Forsvaret nullhus
Publication Year: 2013

Det nye administrasjonsbygget til forsvaret har et årlige beregnet energiforbruk på 16 kWh per kvadratmeter. Dette blir dermed et av landets mest energieffektive kontorbygg. Artikkel skrevet av Mari Gisvold Garathun.


Nanotechnology and possibilities for the thermal building insulation materials of tomorrow are explored within this work. That is, we are looking beyond both the traditional and the state-of-the-art thermal building insulation materials and solutions, e.g. beyond vacuum insulation panels (VIP). Thus advanced insulation material (AIM) concepts like vacuum insulation materials (VIM), gas insulation materials (GIM), nano insulation materials (NIM) and dynamic insulation materials (DIM) are introduced and defined. The VIMs and GIMs have closed pore structures, whereas the NIMs may have either open or closed pore structures. The objective of the DIMs are to dynamically control the thermal insulation material properties, e.g. solid state core conductivity, emissivity and pore gas content. In addition, fundamental theoretical studies aimed at developing an understanding of the basics of thermal conductance in solid state matter at an elementary and atomic level will also be carried out. The ultimate goal of these studies will be to develop tailor-make novel high performance thermal insulating materials and dynamic insulating materials, the latter one making it possible to control and regulate the thermal conductivity in the materials themselves, i.e. from highly insulating to highly conducting.


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